2. The industrial, scientific and medical(ISM) radio bands are
radio bands (portions of the radio spectrum) reserved
internationally for the use of radio frequency for industrial,
scientific and medical purpose other than telecommunications.
Example of applications in these bands include
• Radio frequency process heating
• Microwave oven
• Medical diathermy machines.
INTRODUCTION OF ISM BAND
3.
4. The powerful emissions of these devices can create
electromagnetic interference and disrupt radio communication
using the same frequency so these devices were limited to
certain bands of frequencies.
ISM bands are generally open frequency bands which vary
according to different region and permits.
In general comn eqpts operating in these bands must tolerate
any interference generated by ism applications and users have
no regulatory protection from ISM device operation.
5. Despite the intent of the original allocations, in recent years
the fastest growing uses of these bands have been for short
range, low power wireless comns systems since these
bands can be used without a government license as is
required for transmitters on other frequencies.
Cordless phones , Bluetooth devices near field comn
devices, garage door openers, baby monitors and wireless
computer networks all use the ISM frequencies.
6. SAMPLE OF FREQUNENCY ALLOCATION
FREQ RANGE BNADWIDTH TYPE AVAILABILITY LICENSED USER RMK
2.4GHZ 2.5 GHZ 100 MHZ B WORLDWIDE FIXED, MOBILE
RADIOLCATIONS,
AMATEUR &
AMATEUR SATELLITE
SERVICE
5.725 GHZ 5.875 GHZ 150 MHZ B WORLDWIDE FIXED, SAELLITE ,
RADIOLOCATIN,
MOBILE, AMATEUR&
AMATEUR SATELLITE
SERVICE
24 GHZ 24.25 GHZ 250 MHZ B -DO- AMATEUR &
AMATEUR SATELLITE
RADIOLOCATION&
EARETEH EXPLORATIN
SATELLITE
SERVICE(ACTIVE)
7. HISTORY OF ISM BAND
The ISM bands were first established at the international
telecomm conference of the ITU in Atlantic City, 1947.
The American delegation specifically proposed several bands,
including the now common place 2.4 GHz band to
accommodate the nascent process of microwave heating.
However, FCC annual reports of that time suggest that much
preparation was done ahead of these presentations.
8. From the proceedings the delegate of the United states,
referring to his request that the frequency 2450 Mc/S be
allocated for ISM, indicated that there was in existence in
the United states and working on this frequency diathermy
machine and an electronic coke and that the latter might
eventually be installed in transatlantic ships and airplanes.
There was therefore some point in attempting to reach world
agreement on this subject.
9. Radio frequencies in the ISM bands have been used for
comn purposes although such devices may experience
interference from non comn sources
In the united states as early as 1958 class D citizens
band a part 95 service was allocated to frequencies that
are also allocated to ISM.
In The US the FCC first made unlicensed spread
spectrum available in the ISM bands in rules adopted
on May 9, 1985.
10. Many other countries later developed similar
regulations enabling use of this technology.
The FCC proposed by Michael Marcus of he
RFCC staff in 1980 and the subsequent regulatory
action took five more years.
It was part of a broader proposal to allow civil use
of spread spectrum technology and was opposed at
the tie by mainstream eqpt manufactures and many
radio system operators.
11. 11
APPLICATIONS OF ISM BAND
The original ISM specifications envisioned that the bands
would be used primarily for non Comn. purposes such as
heating .
The bands are still widely used for these purposes. For many
people the most commonly encountered ISM device is the
home microwave oven operating at 2.45 GHz which uses
microwaves to cook food.
12. • Industrial heating is another big application area such
as induction heating , microwave heat treating, plastic
softening and plastic welding processes.
• In medical settings, shortwave and microwave
diathermy machines use radio waves in the ISM bands
to apply deep heating to the body for relaxation and
healing. More recently hyperthermia therapy uses
microwaves to heat tissue to kill cancer cells.
13.
14.
15. 15
Due to the increasing congestion of the radio spectrum,
the increasing sophistication of microelectronics and
the attraction of unlicensed use, these bands are used
for short range Comn. systems for wireless devices
which are now by far the largest uses of these bands.
These are sometimes call Non ISM uses since they do
not fall under industrial, scientific and medical
application areas.
One of he largest applications has been wireless
networking (wi-fi).
16. The IEEE 802.11 wireless networking protocols,
the standards on which almost all wireless
systems are based, use the ISM bands.
Virtually all laptops, tablet computers, computer
printers and cellphones now have 802.11 wireless
modems using 2.4 and 5.7 GHz ISM bands.
Bluetooth is another networking technology using
the 2.4 GHz band.
16
17. Near field Comn. devices such as proximity cards
and contactless smart cards use the lower
frequency 13 and 27 MHZ ISM bands.
Other short range devices using the ISM bands are
wireless microphones, baby monitors, garage
door openers , wireless doorbells, keyless entry
systems for vehicles, radio control channels for
UAVs, wireless surveillance systems.
18. 18
Some electrode less lamp designs are ISM devices which use
RF emission to excite fluorescent tubes. Sulphur lamps are
commercially available plasma lamps , which use a 2.45 Ghz
magnetron to heat sulphur into a brightly glowing plasma
Long distance wieless power systems have been proposed and
experimented with which would use high power transmitters
and rectennas, in lieu of overhead transmission lines and
underground cables, to send power to remote locations.
